Bushings, Grommets
Devices that are used to insulate between an opening in a panel and any items (most often cables and wire) that are inserted into the opening. These devices can also hold the inserted objects securely between the two sides of the opening.

Spiral Wrap, Expandable Sleeving
Hollow tubes of plastic of other materials with both ends open. The tube is split down the length of the tube and the seam is tucked into or over the tube, or the tube has a spiral cut down the length of the tube allowing the item to expand.

Cold Shrink Tape, Tubing
Cold Shrink tubing is hollow pieces of plastic tubing with both ends open. The tubing remains expanded until the center core of the tubing is removed. The tubing then shrinks to seal the items inserted into the tubing. Cold Shrink Tape provides a covering without any adhesive or mastic. The material of the tape reacts with itself to form a protective layer.